The one metal band of their generation routinely touted as potential festival headliners, Avenged Sevenfold have never been short of ambition or tunes, and yet their last two albums were undeniably patchy and unfocused. Seemingly the Californians' first wholesale bid for rock immortality, Hail to the King makes no apologies for its strident saluting of metal's established legends, with several eerily familiar riffs and dynamic moments that Metallica's lawyers might consider a little cheeky. However, shorn of its predecessors' sonic clutter and over-egged arrangements, Hail swiftly turns its old-school preoccupation into a virtue via a stirring, muscular batch of songs. Stripped down to a core of thudding Sabbath-like grooves and brash, spiky vocal refrains, Avenged now sound every bit as vital and imperious as the bands they aspire to emulate. Incalculable hugeness seems pleasingly inevitable.